[flang][OpenMP] Semantic checks for DYN_GROUPPRIVATE

flang/include/flang/Semantics/openmp-modifiers.h

@@ -67,6 +67,7 @@ template <typename SpecificTy> const OmpModifierDescriptor &OmpGetDescriptor();
 #define DECLARE_DESCRIPTOR(name) \
   template <> const OmpModifierDescriptor &OmpGetDescriptor<name>()
 
+DECLARE_DESCRIPTOR(parser::OmpAccessGroup);
 DECLARE_DESCRIPTOR(parser::OmpAlignment);
 DECLARE_DESCRIPTOR(parser::OmpAlignModifier);
 DECLARE_DESCRIPTOR(parser::OmpAllocatorComplexModifier);
@@ -82,6 +83,7 @@ DECLARE_DESCRIPTOR(parser::OmpDependenceType);
 DECLARE_DESCRIPTOR(parser::OmpDeviceModifier);
 DECLARE_DESCRIPTOR(parser::OmpDirectiveNameModifier);
 DECLARE_DESCRIPTOR(parser::OmpExpectation);
+DECLARE_DESCRIPTOR(parser::OmpFallbackModifier);
 DECLARE_DESCRIPTOR(parser::OmpInteropPreference);
 DECLARE_DESCRIPTOR(parser::OmpInteropType);
 DECLARE_DESCRIPTOR(parser::OmpIterator);

flang/lib/Semantics/check-omp-structure.cpp

@@ -682,6 +682,13 @@ void OmpStructureChecker::Enter(const parser::OmpClause::Hint &x) {
   }
 }
 
+void OmpStructureChecker::Enter(const parser::OmpClause::DynGroupprivate &x) {
+  CheckAllowedClause(llvm::omp::Clause::OMPC_dyn_groupprivate);
+  parser::CharBlock source{GetContext().clauseSource};
+
+  OmpVerifyModifiers(x.v, llvm::omp::OMPC_dyn_groupprivate, source, context_);
+}
+
 void OmpStructureChecker::Enter(const parser::OmpDirectiveSpecification &x) {
   // OmpDirectiveSpecification exists on its own only in METADIRECTIVE.
   // In other cases it's a part of other constructs that handle directive
@@ -3316,6 +3323,32 @@ void OmpStructureChecker::Leave(const parser::OmpClauseList &) {
     }
   }
 
+  // Default access-group for DYN_GROUPPRIVATE is "cgroup". On a given
+  // construct there can be at most one DYN_GROUPPRIVATE with a given
+  // access-group.
+  const parser::OmpClause
+      *accGrpClause[parser::OmpAccessGroup::Value_enumSize] = {nullptr};
+  for (auto [_, clause] :
+      FindClauses(llvm::omp::Clause::OMPC_dyn_groupprivate)) {
+    auto &wrapper{std::get<parser::OmpClause::DynGroupprivate>(clause->u)};
+    auto &modifiers{OmpGetModifiers(wrapper.v)};
+    auto accGrp{parser::OmpAccessGroup::Value::Cgroup};
+    if (auto *ag{OmpGetUniqueModifier<parser::OmpAccessGroup>(modifiers)}) {
+      accGrp = ag->v;
+    }
+    auto &firstClause{accGrpClause[llvm::to_underlying(accGrp)]};
+    if (firstClause) {
+      context_
+          .Say(clause->source,
+              "The access-group modifier can only occur on a single clause in a construct"_err_en_US)
+          .Attach(firstClause->source,
+              "Previous clause with access-group modifier"_en_US);
+      break;
+    } else {
+      firstClause = clause;
+    }
+  }
+
   CheckRequireAtLeastOneOf();
 }
 
@@ -5472,7 +5505,6 @@ CHECK_SIMPLE_CLAUSE(Default, OMPC_default)
 CHECK_SIMPLE_CLAUSE(Depobj, OMPC_depobj)
 CHECK_SIMPLE_CLAUSE(DeviceType, OMPC_device_type)
 CHECK_SIMPLE_CLAUSE(DistSchedule, OMPC_dist_schedule)
-CHECK_SIMPLE_CLAUSE(DynGroupprivate, OMPC_dyn_groupprivate)
 CHECK_SIMPLE_CLAUSE(Exclusive, OMPC_exclusive)
 CHECK_SIMPLE_CLAUSE(Fail, OMPC_fail)
 CHECK_SIMPLE_CLAUSE(Filter, OMPC_filter)

flang/lib/Semantics/openmp-modifiers.cpp

@@ -74,6 +74,22 @@ unsigned OmpModifierDescriptor::since(llvm::omp::Clause id) const {
 // Note: The intent for these functions is to have them be automatically-
 // generated in the future.
 
+template <>
+const OmpModifierDescriptor &OmpGetDescriptor<parser::OmpAccessGroup>() {
+  static const OmpModifierDescriptor desc{
+      /*name=*/"access-group",
+      /*props=*/
+      {
+          {61, {OmpProperty::Unique}},
+      },
+      /*clauses=*/
+      {
+          {61, {Clause::OMPC_dyn_groupprivate}},
+      },
+  };
+  return desc;
+}
+
 template <>
 const OmpModifierDescriptor &OmpGetDescriptor<parser::OmpAlignment>() {
   static const OmpModifierDescriptor desc{
@@ -321,6 +337,22 @@ const OmpModifierDescriptor &OmpGetDescriptor<parser::OmpExpectation>() {
   return desc;
 }
 
+template <>
+const OmpModifierDescriptor &OmpGetDescriptor<parser::OmpFallbackModifier>() {
+  static const OmpModifierDescriptor desc{
+      /*name=*/"fallback-modifier",
+      /*props=*/
+      {
+          {61, {OmpProperty::Unique}},
+      },
+      /*clauses=*/
+      {
+          {61, {Clause::OMPC_dyn_groupprivate}},
+      },
+  };
+  return desc;
+}
+
 template <>
 const OmpModifierDescriptor &OmpGetDescriptor<parser::OmpInteropPreference>() {
   static const OmpModifierDescriptor desc{

flang/test/Semantics/OpenMP/dyn-groupprivate.f90

@@ -0,0 +1,8 @@
+!RUN: %python %S/../test_errors.py %s %flang -fopenmp -fopenmp-version=61
+
+subroutine f00(x)
+  integer :: x
+  !ERROR: The access-group modifier can only occur on a single clause in a construct
+  !$omp target dyn_groupprivate(cgroup: x), dyn_groupprivate(10)
+  !$omp end target
+end